The New JC777
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I keep blowing 400 amp t-fuses when charging at 240 amps
- Thread starter JedTheFed
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I can't find a spec sheet either (or an AIC rating, if no AIC is stated, its unlikely to be a suitable replacement for a Class T fuse)
The New JC777
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The doc I posted has a interrupt rating of 100kA @ 65 vdc. Or am I reading it wrong?
@Robin Gudgel will know the AIC of the GJ series breakers
I think you are reading it right, its an impressive rating, but it looks like that spec sheet is for a different brand (Eaton) and model of fuse than the one you posted earlier (the $83 Schneider) which is what @HRTKD and I were replying to.
I looked at the GJ series from the doc you posted. The specs look great at first glance, but the only place I could find selling it (just a quick search) that listed a price is charging $478 ?
eXodus
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It got really hot then.
Can't you redesign your system? so that each inverter goes with a separate fuse to the busbar and another fuse for each battery? Then you don't need to deal with such large currents on one fuse. 400A is a lot.
I personally try not to go far above 150A with any single item. (Ideal less then 100A) Your case proofs what I'm doing for years.
chrisski
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Have you considered redoing the connectors at the fuse holder? Possibly a bad crimp or Lug. I use pre-tinned UL rated lugs and those are are thicker than the non-UL lugs I can buy.
Would be nice to see pictures of what is blowing. THe only picture I saw from the OP was in post #50 and showed a switch similar to what I have. The ad I bought it from claims 250 amps at 12 volts, 125 amps at 24 volts, and is non-UL rated.
diysolarforum.com
A picture of the fuse holder would help. As mentioned by @HRTKD the busbar connections need to be flat and won’t flex. I think a 1/200 th of an inch will make a difference, at least that’s how far off I think one of my busbars was. So little you could barely see. My technique is to tighten the bus bar first on both devices, and then secure the mount.
I have only bought Blue Sea Class T fuse holders and those have lugs the larger fuses 225 amps+ were 5/16ths and the smaller fuse <225 amps were 1/4 inch. Someone mentioned Class T fuse holders with Ferrules. I have not seen those.
Would be nice to see pictures of what is blowing. THe only picture I saw from the OP was in post #50 and showed a switch similar to what I have. The ad I bought it from claims 250 amps at 12 volts, 125 amps at 24 volts, and is non-UL rated.
I keep blowing 400 amp t-fuses when charging at 240 amps
https://www.invertersupply.com/index.php?main_page=product_info&products_id=6321 EATON HEINEMANN 250 amp GJ series breaker. A Canadian company. Very old school and very industrial quality. Maybe one each per inverter to bussbar and a seperate similar breaker for the Coach 12 volt system. The...
diysolarforum.com
A picture of the fuse holder would help. As mentioned by @HRTKD the busbar connections need to be flat and won’t flex. I think a 1/200 th of an inch will make a difference, at least that’s how far off I think one of my busbars was. So little you could barely see. My technique is to tighten the bus bar first on both devices, and then secure the mount.
I have only bought Blue Sea Class T fuse holders and those have lugs the larger fuses 225 amps+ were 5/16ths and the smaller fuse <225 amps were 1/4 inch. Someone mentioned Class T fuse holders with Ferrules. I have not seen those.
John Frum
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Depending on how the 8x batteries are paralleled you may not need a pre-charge circuit.
I think I already linked https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf
Jed, if you have things melting, it usually indicates a bad connection or too small of a wire size for the amount of current. What gauge wire are you using to and from the fuse holder? Do you have an infrared thermometer to use to check the temperature of your setup while it is running? How about a friend with an infrared camera? They help immensely. Look for bad connections in terminal ends on the cable, too.
You mentioned that your battery bay is hot. That's not good for batteries, inverters, or controllers, so that's yet another issue which can lead up to short lifetimes of your components, so do fix that soon.
If you don't have any of that equipment, put on a pair of nitrile gloves and feel the connections when it's running high amperage. Most should be not much warmer than room temperature. Anything which feels hot usually has a bad connection or is a bad part. Try a circuit breaker in that spot.
You mentioned that your battery bay is hot. That's not good for batteries, inverters, or controllers, so that's yet another issue which can lead up to short lifetimes of your components, so do fix that soon.
If you don't have any of that equipment, put on a pair of nitrile gloves and feel the connections when it's running high amperage. Most should be not much warmer than room temperature. Anything which feels hot usually has a bad connection or is a bad part. Try a circuit breaker in that spot.
Stud Connector is the answer. I had the same problem. If you have stranded welding cable and put it in those screw down connectors like you have you get excessive heat. You can put the stranded ends in ferrules first and try it but I bought a T-Fuse holder with studs for a lug connection and that solved all of my problems. Bad connection= Heat.
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